/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */
package wx.xml.xalan.xml.dtm;

/**
 * This class iterates over a single XPath Axis, and returns node handles.
 */
public interface DTMAxisIterator extends Cloneable {

    /**
     * Specifies the end of the iteration, and is the same as DTM.NULL.
     */
    public static final int END = DTM.NULL;

    /**
     * Get the next node in the iteration.
     *
     * @return The next node handle in the iteration, or END.
     */
    public int next();


    /**
     * Resets the iterator to the last start node.
     *
     * @return A DTMAxisIterator, which may or may not be the same as this
     * iterator.
     */
    public DTMAxisIterator reset();

    /**
     * @return the number of nodes in this iterator.  This may be an expensive
     * operation when called the first time.
     */
    public int getLast();

    /**
     * @return The position of the current node in the set, as defined by XPath.
     */
    public int getPosition();

    /**
     * Remembers the current node for the next call to gotoMark().
     */
    public void setMark();

    /**
     * Restores the current node remembered by setMark().
     */
    public void gotoMark();

    /**
     * Get start to END should 'close' the iterator,
     * i.e. subsequent call to next() should return END.
     *
     * @return The root node of the iteration.
     */
    public int getStartNode();

    /**
     * Set start to END should 'close' the iterator,
     * i.e. subsequent call to next() should return END.
     *
     * @param node Sets the root of the iteration.
     * @return A DTMAxisIterator set to the start of the iteration.
     */
    public DTMAxisIterator setStartNode(int node);

    /**
     * @return true if this iterator has a reversed axis, else false.
     */
    public boolean isReverse();

    /**
     * @return a deep copy of this iterator. The clone should not be reset
     * from its current position.
     */
    public DTMAxisIterator cloneIterator();

    /**
     * Set if restartable.
     */
    public void setRestartable(boolean isRestartable);

    /**
     * Return the node at the given position.
     *
     * @param position The position
     * @return The node at the given position.
     */
    public int getNodeByPosition(int position);
}
